The present invention relates to a device for measuring immunochromatography test pieces.
In immunochromatography analysis, antibodies (or antigens) which provoke a antigen or antibody reaction with antigens (or antibodies) in a subject (sample) are previously coated in strips onto prescribed positions of an immunochromatography test piece. After applying a subject to an immunochromatography test piece, the antigens (or antibodies) in the subject are dissolved out using a developer solution, and are caused to impregnate into the immunochromatography test piece, whereupon the antigens (or antibodies) in the subject are trapped by an antigen or antibody reaction in the region of the antigens (or antibodies) coated onto the immunochromatography test piece. Since the quantity trapped is the total amount of that antigen (or antibody) in the subject, it is possible to measure the total amount of the antigen (or antibody) by means of optical measurement, such as light absorption, or the like, if the antigen (or antibody) in the subject is previously marked by a dye. Immunochromatography analysis can be used for measuring extremely small quantities, compared to standard colorimetric methods.
Japanese Patent Laid-open No. H7-5110 discloses a measuring device for measuring the concentration of a specific material in a subject from an immunochromatography test piece after development and dying of the subject. In the measuring device described in Japanese Patent Laid-open No. H7-5110, light from an LED is irradiated onto an immunochromatography test piece, the light reflected from the immunochromatography test piece is detected by a CCD color image sensor, and the degree of coloration is identified.
In an immunochromatography test piece, the portion which is colored by the antigen or antibody reaction extends in a direction which intersects with the path of movement of the subject, and cases are observed wherein uneven coloring occurs in the direction in which the colored portion extends. If uneven coloring occurs in the colored portion in this way, then it becomes difficult to measure the degree of coloring with good accuracy.
The present invention was devised with the foregoing in view, an object thereof being to provide a measuring device for immunochromatography test pieces which is capable of measuring the degree of coloring of immunochromatography test pieces to a high level of accuracy.
In order to achieve the aforementioned object, the measuring device for immunochromatography test pieces according to the present invention is a measuring device for immunochromatography test pieces, comprising an irradiation optical system for irradiating measurement light onto immunochromatography test pieces; and a detection optical system for detecting light from the immunochromatography test pieces due to the measurement light; characterized in that the detection optical system comprises a cylindrical lens and an imaging element; and the cylindrical lens is disposed in such a manner that the direction of the generating line thereof intersects with the direction of travel of antigens or antibodies in the immunochromatography test piece, and creates an image of a pattern formed in a direction intersecting with the direction of travel of the antigens or antibodies, on the imaging element, due to the irradiation of the measurement light from the irradiation optical system.
The detection optical system has a cylindrical lens and an imaging element, and in particular, the cylindrical lens is disposed in such a manner that the direction of the generating line thereof intersects with the direction of travel of antigens or antibodies in the immunochromatography test piece, and creates an image of a pattern formed in a direction intersecting with the direction of travel of the antigens or antibodies, on the imaging element, due to the irradiation of the measurement light from the irradiation optical system. Therefore, light that is parallel to the direction of travel of the antigens or antibodies in the immunochromatography test piece is formed as an image on the imaging element, and light that is orthogonal to the direction of travel of the antigens or antibodies in the immunochromatography test piece is defocused and equalized. Consequently, even if there is unevenness in the coloration in the direction of extension of the colored region, then the uneven coloration is optically equalized by the cylindrical lens, and a pattern wherein uneven coloration is optically equalized is formed as an image on the imaging element. As a result, it is possible to measure the degree of coloration of the immunochromatography test piece with a high level of accuracy.
The measuring device for immunochromatography test pieces according to the present invention may be further characterized in that a member formed with a slit extending in the direction of the generating line of the cylindrical lens is further provided between the immunochromatography test piece and the cylindrical lens.
By providing a member formed with a slit extending in the direction of the generating line of the cylindrical lens between the immunochromatography test piece and the cylindrical lens, it is possible to form an image having little aberration on the imaging element.
Moreover, the measuring device for immunochromatography test pieces according to the present invention may be further characterized in that the imaging element is a linear image sensor wherein a plurality of light-receiving elements are arrayed in a direction approximately orthogonal to the direction of the generating line of the cylindrical lens.
By using a linear image sensor wherein a plurality of light-receiving elements are arrayed in a direction approximately orthogonal to the direction of the generating line of the cylindrical lens, it is possible to realize a measuring device having an inexpensive and compact composition. As described above, since the uneven coloration is optically equalized by the cylindrical lens, then the degree of coloration of the immunochromatography test piece can be measured with good accuracy, even if a linear image sensor is used as the imaging element.
Furthermore, the measuring device for immunochromatography test pieces according to the present invention may be further characterized in that the irradiation optical system and the detection optical system are disposed in such a manner that the imaging element receives the transmitted light of the measurement light irradiated onto the immunochromatography test piece; and the light absorption of the color pattern is measured on the basis of the transmitted light received by the imaging element.
The degree of coloration of the immunochromatography test piece can be measured simply and very accurately. Consequently, the total amount of antigens or antibodies can be measured precisely.
The measuring device for immunochromatography test pieces according to the present invention may be further characterized in that the irradiation optical system and the detection optical system are disposed in such a manner that the imaging element receives the reflected light of the measurement light irradiated onto the immunochromatography test piece; and the reflectivity of the color pattern is measured on the basis of the reflected light received by the imaging element.
The degree of coloration of the immunochromatography test piece can be measured simply and very accurately. Consequently, the total amount of antigens or antibodies can be measured precisely.